account-financial-reporting/account_financial_report_qweb/report/templates/layouts.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>

    <template id="assets_specific" inherit_id="report.assets_common">
        <xpath expr="." position="inside">
            <link href="/account_financial_report_qweb/static/src/css/report.css" rel="stylesheet"/>
        </xpath>
    </template>

    <template id="account_financial_report_qweb.internal_layout">
        <t t-raw="0" />
        <div class="footer">
            <div class="row">
                <div class="col-xs-6 custom_footer">
                    <span t-esc="context_timestamp(datetime.datetime.now()).strftime('%Y-%m-%d %H:%M')"/>
                </div>
                <div class="col-xs-6 text-right custom_footer">
                    <ul class="list-inline">
                        <li><span class="page"/></li>
                        <li>/</li>
                        <li><span class="topage"/></li>
                    </ul>
                </div>
            </div>
        </div>
    </template>

</odoo>